xmlmodule.c

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/*
 * xmlmodule.c : basic API for dynamic module loading added 2.6.17
 *
 * See Copyright for the status of this software.
 *
 * joelwreed@comcast.net
 *
 * http://www.fortran-2000.com/ArnaudRecipes/sharedlib.html
 */
 
/* In order RTLD_GLOBAL and RTLD_NOW to be defined on zOS */
#if defined(__MVS__)
#define _UNIX03_SOURCE
#endif
 
#define IN_LIBXML
#include "libxml.h"
 
#include <string.h>
#include <libxml/xmlmemory.h>
#include <libxml/xmlerror.h>
#include <libxml/xmlmodule.h>
#include <libxml/globals.h>
 
#ifdef LIBXML_MODULES_ENABLED
 
struct _xmlModule {
    unsigned char *name;
    void *handle;
};
 
static void *xmlModulePlatformOpen(const char *name);
static int xmlModulePlatformClose(void *handle);
static int xmlModulePlatformSymbol(void *handle, const char *name, void **result);
 
/************************************************************************
 *                                  *
 *      module memory error handler             *
 *                                  *
 ************************************************************************/
 
static void
xmlModuleErrMemory(xmlModulePtr module, const char *extra)
{
    const char *name = NULL;
 
    if (module != NULL) {
        name = (const char *) module->name;
    }
 
    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
                    XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0, extra,
                    name, NULL, 0, 0,
                    "Memory allocation failed : %s\n", extra);
}
 
xmlModulePtr
xmlModuleOpen(const char *name, int options ATTRIBUTE_UNUSED)
{
    xmlModulePtr module;
 
    module = (xmlModulePtr) xmlMalloc(sizeof(xmlModule));
    if (module == NULL) {
        xmlModuleErrMemory(NULL, "creating module");
        return (NULL);
    }
 
    memset(module, 0, sizeof(xmlModule));
 
    module->handle = xmlModulePlatformOpen(name);
 
    if (module->handle == NULL) {
        xmlFree(module);
        __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
                        XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
                        name, NULL, 0, 0, "failed to open %s\n", name);
        return(NULL);
    }
 
    module->name = xmlStrdup((const xmlChar *) name);
    return (module);
}
 
int
xmlModuleSymbol(xmlModulePtr module, const char *name, void **symbol)
{
    int rc = -1;
 
    if ((NULL == module) || (symbol == NULL) || (name == NULL)) {
        __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
                        XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
                        NULL, NULL, 0, 0, "null parameter\n");
        return rc;
    }
 
    rc = xmlModulePlatformSymbol(module->handle, name, symbol);
 
    if (rc == -1) {
        __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
                        XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
                        name, NULL, 0, 0,
                        "failed to find symbol: %s\n",
            (name == NULL ? "NULL" : name));
        return rc;
    }
 
    return rc;
}
 
int
xmlModuleClose(xmlModulePtr module)
{
    int rc;
 
    if (NULL == module) {
        __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
                        XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, 0,
                        NULL, NULL, 0, 0, "null module pointer\n");
        return -1;
    }
 
    rc = xmlModulePlatformClose(module->handle);
 
    if (rc != 0) {
        __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
                        XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, 0,
                        (const char *) module->name, NULL, 0, 0,
                        "failed to close: %s\n", module->name);
        return -2;
    }
 
    rc = xmlModuleFree(module);
    return (rc);
}
 
int
xmlModuleFree(xmlModulePtr module)
{
    if (NULL == module) {
        __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
                        XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, NULL,
                        NULL, NULL, 0, 0, "null module pointer\n");
        return -1;
    }
 
    xmlFree(module->name);
    xmlFree(module);
 
    return (0);
}
 
#if defined(HAVE_DLOPEN) && !defined(_WIN32)
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
 
#ifndef RTLD_GLOBAL            /* For Tru64 UNIX 4.0 */
#define RTLD_GLOBAL 0
#endif
 
static void *
xmlModulePlatformOpen(const char *name)
{
    return dlopen(name, RTLD_GLOBAL | RTLD_NOW);
}
 
/*
 * xmlModulePlatformClose:
 * @handle: handle to the module
 *
 * returns 0 on success, and non-zero on error.
 */
 
static int
xmlModulePlatformClose(void *handle)
{
    return dlclose(handle);
}
 
/*
 * xmlModulePlatformSymbol:
 * http://www.opengroup.org/onlinepubs/009695399/functions/dlsym.html
 * returns 0 on success and the loaded symbol in result, and -1 on error.
 */
 
static int
xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
{
    *symbol = dlsym(handle, name);
    if (dlerror() != NULL) {
    return -1;
    }
    return 0;
}
 
#else /* ! HAVE_DLOPEN */
 
#ifdef HAVE_SHLLOAD             /* HAVE_SHLLOAD */
#ifdef HAVE_DL_H
#include <dl.h>
#endif
/*
 * xmlModulePlatformOpen:
 * returns a handle on success, and zero on error.
 */
 
static void *
xmlModulePlatformOpen(const char *name)
{
    return shl_load(name, BIND_IMMEDIATE, 0L);
}
 
/*
 * xmlModulePlatformClose:
 * returns 0 on success, and non-zero on error.
 */
 
static int
xmlModulePlatformClose(void *handle)
{
    return shl_unload(handle);
}
 
/*
 * xmlModulePlatformSymbol:
 * http://docs.hp.com/en/B2355-90683/shl_load.3X.html
 * returns 0 on success and the loaded symbol in result, and -1 on error.
 */
 
static int
xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
{
    int rc;
 
    errno = 0;
    rc = shl_findsym(&handle, name, TYPE_UNDEFINED, symbol);
    return rc;
}
 
#endif /* HAVE_SHLLOAD */
#endif /* ! HAVE_DLOPEN */
 
#if defined(_WIN32)
 
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
 
/*
 * xmlModulePlatformOpen:
 * returns a handle on success, and zero on error.
 */
 
static void *
xmlModulePlatformOpen(const char *name)
{
    return LoadLibraryA(name);
}
 
/*
 * xmlModulePlatformClose:
 * returns 0 on success, and non-zero on error.
 */
 
static int
xmlModulePlatformClose(void *handle)
{
    int rc;
 
    rc = FreeLibrary(handle);
    return (0 == rc);
}
 
/*
 * xmlModulePlatformSymbol:
 * http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/getprocaddress.asp
 * returns 0 on success and the loaded symbol in result, and -1 on error.
 */
 
static int
xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
{
XML_IGNORE_PEDANTIC_WARNINGS
    *symbol = GetProcAddress(handle, name);
    return (NULL == *symbol) ? -1 : 0;
XML_POP_WARNINGS
}
 
#endif /* _WIN32 */
 
#ifdef HAVE_BEOS
 
#include <kernel/image.h>
 
/*
 * xmlModulePlatformOpen:
 * beos api info: http://www.beunited.org/bebook/The%20Kernel%20Kit/Images.html
 * returns a handle on success, and zero on error.
 */
 
static void *
xmlModulePlatformOpen(const char *name)
{
    return (void *) load_add_on(name);
}
 
/*
 * xmlModulePlatformClose:
 * beos api info: http://www.beunited.org/bebook/The%20Kernel%20Kit/Images.html
 * returns 0 on success, and non-zero on error.
 */
 
static int
xmlModulePlatformClose(void *handle)
{
    status_t rc;
 
    rc = unload_add_on((image_id) handle);
 
    if (rc == B_OK)
        return 0;
    else
        return -1;
}
 
/*
 * xmlModulePlatformSymbol:
 * beos api info: http://www.beunited.org/bebook/The%20Kernel%20Kit/Images.html
 * returns 0 on success and the loaded symbol in result, and -1 on error.
 */
 
static int
xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
{
    status_t rc;
 
    rc = get_image_symbol((image_id) handle, name, B_SYMBOL_TYPE_ANY, symbol);
 
    return (rc == B_OK) ? 0 : -1;
}
 
#endif /* HAVE_BEOS */
 
#ifdef HAVE_OS2
 
#include <os2.h>
 
/*
 * xmlModulePlatformOpen:
 * os2 api info: http://www.edm2.com/os2api/Dos/DosLoadModule.html
 * returns a handle on success, and zero on error.
 */
 
static void *
xmlModulePlatformOpen(const char *name)
{
    char errbuf[256];
    void *handle;
    int rc;
 
    rc = DosLoadModule(errbuf, sizeof(errbuf) - 1, name, &handle);
 
    if (rc)
        return 0;
    else
        return (handle);
}
 
/*
 * xmlModulePlatformClose:
 * os2 api info: http://www.edm2.com/os2api/Dos/DosFreeModule.html
 * returns 0 on success, and non-zero on error.
 */
 
static int
xmlModulePlatformClose(void *handle)
{
    return DosFreeModule(handle);
}
 
/*
 * xmlModulePlatformSymbol:
 * os2 api info: http://www.edm2.com/os2api/Dos/DosQueryProcAddr.html
 * returns 0 on success and the loaded symbol in result, and -1 on error.
 */
 
static int
xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
{
    int rc;
 
    rc = DosQueryProcAddr(handle, 0, name, symbol);
 
    return (rc == NO_ERROR) ? 0 : -1;
}
 
#endif /* HAVE_OS2 */
 
#endif /* LIBXML_MODULES_ENABLED */